package 链表.middle;

/**
 * @author Lw中
 * @date 2020/9/27 11:06
 */
public class Er {

    public class ListNode {
      int val;
      ListNode next;
      ListNode(int x) { val = x; }
    }

    /**
     * LWZ TODO : 2020/9/27 毫无头绪
     *
     */
    /**
     * 两数相加
     * @param l1
     * @param l2
     * @return
     */
    public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
        ListNode pre = new ListNode(0);
        ListNode cur = pre;
        int carry = 0;
        while(l1 != null || l2 != null) {
            int x = l1 == null ? 0 : l1.val;
            int y = l2 == null ? 0 : l2.val;
            int sum = x + y + carry;

            carry = sum / 10;
            sum = sum % 10;
            cur.next = new ListNode(sum);

            cur = cur.next;
            if(l1 != null) {
                l1 = l1.next;
            }
            if(l2 != null) {
                l2 = l2.next;
            }
        }
        if(carry == 1) {
            cur.next = new ListNode(carry);
        }
        return pre.next;
    }

    public static void main(String[] args) {

    }

}
